Seyed Majid Reza Hosseini Mofrad; Hassan Ahmadi; Ali Akbar Mehrabi; Baharak Motamedvaziri
Abstract
For this purpose, according to Cochran's equation, from Hashtgerd-Taleghan asphalt road 26 km long and Hashtgerd-Taleghan dirt road 9 km long, road sedimentation was calculated with 17 and 11 samples, respectively, and finally, using statistical relationships, the erosion rate was calculated. And sedimentation ...
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For this purpose, according to Cochran's equation, from Hashtgerd-Taleghan asphalt road 26 km long and Hashtgerd-Taleghan dirt road 9 km long, road sedimentation was calculated with 17 and 11 samples, respectively, and finally, using statistical relationships, the erosion rate was calculated. And sedimentation was estimated in the entire route. By direct measurement of erosion, the total sediments remaining along the route were equal to 17259.32 tons per year, of which 6241.45 tons per year are related to the excavation wall and 11017.87 tons per year are related to the embankment wall. Using the WARSEM model, the total amount of sedimentation from asphalt and dirt roads was estimated as 15172.67 tons per year, equivalent to 52.14 tons per hectare per year, of which 9464.53 tons per year, equivalent to 48.03 tons. Per hectare per year, the contribution of the excavation wall and the embankment wall of the asphalt road is 14.5708 tons per year, which is equivalent to 22.63 tons per hectare per year, the contribution of the excavation wall and the embankment wall of the dirt road. The sensitivity of the WARSEM model for the standardized parameters for the asphalt road showed that the slope and geological factors are important factors in the sedimentation of the embankment wall and the height factor of the embankment wall is a very important parameter in the sedimentation of the embankment wall. The sensitivity of the model on the dirt road according to this score of the parameters was very close to each other.
Saeed Pourheadari; Hassan Ahmadi; ِAbolfazl Moeini; Sadat Feiznia; Mohammad Jafari
Abstract
Due to physical and chemical composition and lack of vegetation cover and therefore less organic matter, Marlons formations are the most sensitive formations to erosion, so that by removing the particles of the soil and transporting their to the lower regions, cause different forms of erosions. Due to ...
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Due to physical and chemical composition and lack of vegetation cover and therefore less organic matter, Marlons formations are the most sensitive formations to erosion, so that by removing the particles of the soil and transporting their to the lower regions, cause different forms of erosions. Due to the physical and chemical properties of marls, the study area has caused various types of erosion in the basin and downstream urban areas has been affected followed by mudflows resulting from their erosion and sedimentation. In this research, 35 soil samples were taken from the different work units to determine the physical and chemical characteristics and also to study the soil losses using a rain simulator. Along to this, 5 samples from particular marl units of the area was taken and transferred to the laboratory for mineralogical experiments. The K method in the global erosion equation was used to evaluate the degradability of detached materials that according to this method, the highest value of k is related to forms with a coefficient of 70%, and the least of which is the surface and rainfall erosion form with a coefficient of 25%. Also, due to the fact that there were 4 units of work with attached materials, the stripy method was used to evaluate their erodibility.
maryam mombeni; hamid reza asgari; ali Mohammadian Behbahani; Salman Zare; hossein yousefi
Abstract
One of the main challenges of land degradation management in arid and desert areas of Iran is the stabilization of sand as well as the control of dust; therefore the use of mulches, particularly eco-friendly mulch, is one of the ways to stabilize sand used. The purpose of this study was to investigate ...
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One of the main challenges of land degradation management in arid and desert areas of Iran is the stabilization of sand as well as the control of dust; therefore the use of mulches, particularly eco-friendly mulch, is one of the ways to stabilize sand used. The purpose of this study was to investigate the possibility of using residues such as black liqueur and malass as mulch to stabilize the sand. To prepare the substrate for treatments in the laboratory environment, Rig Boland sandy of Kashan was used. Metal trays with dimensions of 100 × 30 × 2 cm were used for the experiments. For spraying of malass, black liquor and control treatments in a single layer and double layer of 2.5-liter sprinkler were applied and a completely randomized design with three replications was performed. To evaluate the performance of these materials, the shear strength, saturation, and dry strength and water permeability were measured and the data were analyzed by appropriate statistical software. In vitro results showed that the penetration resistance of molasses and black liqueur mulches were 9.8 and 7.8 kN/m2, respectively. These two types of mulch have significant differences with each other and with control (water) treatment. The highest penetration and shear strength were related to Malass treatment, which increased the penetration resistance by 9.8 times and the shear resistance by 14 times. The infiltration rate in one-layer liqueur mulch was significantly different compared to Malass and control (water) mulches, while the infiltration rate decreased with increasing thickness.
Delaram Ziaei; Rafat Zare Bidaki; Aliasghar Besalatpour
Abstract
Knowing the amount of runoff and sediment generated from different lands is an important step in land use management. Since it is not always possible to measure these values, modeling parameters, will be a way to achieve watershed comprehensive management. Beheshtabad watershed in Chaharmahal & Bakhtiari ...
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Knowing the amount of runoff and sediment generated from different lands is an important step in land use management. Since it is not always possible to measure these values, modeling parameters, will be a way to achieve watershed comprehensive management. Beheshtabad watershed in Chaharmahal & Bakhtiari province with different land uses such as range land, agriculture, gardens and urban area is an important part of Northern Karun Basin. In order to simulate the amount of runoff and sediment generated in different land uses, SWAT model was used. Discharge and sediment data of weather and hydrometric stations located in the area was used for sensitivity analyses and then to calibrate and validate model by SUFI-2 algorithm. NS and R² coefficients obtained for runoff calibration are respectively 0.69, 0.71 and for runoff validation are 0.65, 0.67 and for sediment are 0.72, 0.73 in calibration, and 0.66, 0.71 in validation, that confirmed model ability to accurately estimate of flow, runoff and sediment in the study area. The results showed that dry farming lands with average runoff and sediment of 190 mm, 24.5 tons per hectare per year respectively, has the highest and gardens with an average of 80 mm runoff has the lowest sediment yield of 1.63 tons per hectare in the year.
Seyed Masoud Soleimanpour; Bahram Hedayati; Majid Soufi; Mohammad Javad Rousta; Samad Shadfar
Abstract
One of the important relations in the erosion of gullies is to study the threshold of erosion creation and expansion. In recent decade, creation of new knowledge in determination of relation between variables was led to develop prediction methods in different science and therefore, investigating the ...
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One of the important relations in the erosion of gullies is to study the threshold of erosion creation and expansion. In recent decade, creation of new knowledge in determination of relation between variables was led to develop prediction methods in different science and therefore, investigating the ability to use these methods in erosion and soil conservation is essential. Also, in order to control the erosion of the gully, the mechanism of gullies growth and its dimension expansion, especially increasing in gullies length, has to be carefully determine; for this purpose, the present study aimed to determine the threshold of the most effective factors on increasing the length of the gully, using the K-Means data mining algorithms and the CART decision tree in the Ghazian watershed in the north of Fars province. The results of this study, which include measuring various variables of gullies under field condition and in laboratory, and using data mining techniques, showed that increasing the length of gully in this area depended on the factors of the area above headcut, saturated extract electrical conductivity, forehead slope, canopy cover percentage, and sodium adsorption ratio. It is recommended control of erosion in the foreheads is highly important in reducing the increase in gullies length and sediment production. Also, improving the soils of this area with soil amendments and the restoration of compatible vegetation and the increase in soil organic matter should be considered as the priority of effective actions to control the increasing length of gullies.
Mehdi Vatakhah; Mohsen Mohsenisaravi; Hasan Ahmadi
Abstract
Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, ...
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Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427.23 ha in area. To achieve this propose, area, erosion rate and net income value of each land uses according to requiring standards of each land uses area was extracted. Then, limitations and two objective functions were determined and optimization problem was solved by using ADBASE software. The results revealed that the optimization decrease 6.99 percent of erosion rate(6.28 ton/ha/year to 5.84 ton/ha/year) and 4.65 percent of pure income(118174.38 to 112681.02 million Rials). Also, the results proposed that drylands farming are changed to garden and orchard and rangelands.
yahya Parvizi; mohammad gheitury; Mosieb Heshmati
Abstract
The WEPP physically model is able to dynamically simulate runoff and soil erosion using physical concepts of erosion and hydraulic of overland flow science considering plant growth, residue decomposition, winter process. Determination of the capability of this model in runoff and erosion estimation in ...
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The WEPP physically model is able to dynamically simulate runoff and soil erosion using physical concepts of erosion and hydraulic of overland flow science considering plant growth, residue decomposition, winter process. Determination of the capability of this model in runoff and erosion estimation in different range type with investigation the effects of management were the main objectives of this research. This research was conducted in the Kabode placed across the Gharasoo watershed by installing erosion plot with dimension of 10×3 meter and three replications in three range types at the slopes of 25, 35 and 45%. Climate data including rainfall and air temperature was recorded in the site and additional data including wind velocity and direction, solar radiation and dew point temperature was prepared from Kermanshah synoptic climate station. Event based erosion and runoff was simulated in each plot by the v2008.9 version of the model. Results from model assessment for prediction of runoff indicated that the maximum model accuracy was in 45% slope. Also, mode relative error in runoff in 25 and 35% slope was about 0.61 liter. Overall, model performance in runoff estimation was sought in all three slopes, so that Nash-Sutcliff index was 0.96 to 0.73. Minimum and maximum estimation error in erosion prediction was occurred in 35 and 45% slope, respectively. Model prediction results indicated under-estimation in all the slopes. Negative amounts of Nash-Sutcliff index indicated confirms the low efficiency model especially in conditions prevailing in two slopes of 25 and 35%.
Ali Golkarian
Abstract
Erosion is one of the important factors in soil degradation and decrease fertility and slope length is one of the most effective factors in land form and amount of erosion. The objective of this study was investigation of spatially variation of sediment concentration in slope length until to receive ...
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Erosion is one of the important factors in soil degradation and decrease fertility and slope length is one of the most effective factors in land form and amount of erosion. The objective of this study was investigation of spatially variation of sediment concentration in slope length until to receive transport capacity. To obtain this goal a hill slope simulator system designed and manufactured. This system include 10 flumes, each has five meter length which after series them become fifty meters. This system can produce cumulative flow via fifty watering can tube which are install on flumes with one meter interval and each flume discharging is 100 cc. Other variables include two type of soil and slope in three level 15, 22.5, 30 percent. Three replications were used for each treatment and totally 18 experiment was done. In each experiment four samples were gathered from end of each flume and concentration was determined. Complete randomized design with factorial arrangement was used for data analyzing. Richard’s function was used for fitting a suitable curve on observed data. Result was shown that effect of soil type on sediment concentration was not significant while slope and slope length effects was significant. Otherwise sediment concentration in the two last flumes was located in same class which is shown that sediment concentration achieved to transport capacity in this slope length. Also results were shown that Richard’s function can simulate trend of concentration variety in slope length.
Aliakbar Nazari Samani; Fatemeh Avazadeh Tavakoli; Hassan Ahmadi; Gholamreza Rahi
Abstract
Gully erosion is one of the most destructive types of channeled water erosion that removes aconsiderable volume of soil as it develops. This type of erosion consists of complex a geomorphicprocess that has been known as an indicator of accelerated soil erosion. In this research theadvancement of 25 headcuts ...
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Gully erosion is one of the most destructive types of channeled water erosion that removes aconsiderable volume of soil as it develops. This type of erosion consists of complex a geomorphicprocess that has been known as an indicator of accelerated soil erosion. In this research theadvancement of 25 headcuts were assessed through digital interpretation of multi-temporal aerialphotos, field observations and GIS data analysis over the two periods of 1967-1995 and 1995-2008.Moreover, the stepwise regression analysis procedure was applied to extract the effective factors ongully head advancement (such as topography, physico-chemical soil attributes and morphology ofgully). The results indicated that the mean of gully head advancement over the periods of 1967-1995,1995-2008 and the mean of two periods were measured 1.36, 1.23 and 1.3 m/y, respectively. Further,regression analysis revealed that headcut's contribution area, distance of gully-head to ridge, height ofgully head cut and SAR are the main factors on gully head advancement. Therefore, distance to ridge,headcut high and presence of plunge pool could use as suitable criteria to distinguish the active gulliesin order to prioritizing the conservation activities.
